Baking oven

ABSTRACT

Into the baking chamber of a baking oven a carriage (7) carrying the baking goods (5) can be shifted in between two partition walls (13) having horizontal slots (14) through which hot air is blown into the baking chamber (4) in alternating directions. The carriage (7) carries channels (21) joining the slots (14) and being confined by guide sheet metal elements (20). By these channels (21) the air passing through the slots (14) is guided towards the center of the carriage and onto the baking good.

This is a continuation of application Ser. No. 864,698, filed Apr. 8,1986, now abandoned.

BACKGROUND OF THE INVENTION

The invention refers to a baking oven comprising a baking chamber intowhich a carriage can be shifted which carries the baking good on supportmembers, in particular baking plates, and which is stationary during thebaking process, noting that air channels extend at both sides of thebaking chamber over the height of the baking chamber from top to bottom,which air channels are separated from the baking chamber by partitionwalls having provided therein air flow openings formed by horizontalslots preferably extending over the whole depth of the support membersas measured in shifting direction of the carriage, heated air beingblown in alternating direction into the baking chamber by means of ablower.

Such baking ovens comprising a carriage being stationary during thebaking process suffer frequently from the drawback, that the baking gooddistributed over the support members of the carriage is not uniformelybaked. Experiments have shown that the reason for this has its origin inthe fact that the heated air supplied via one of both air channels,although emerging with high speed from the air flow passages, becomesrapidly decelerated and thus arrives at the baking good with onlyreduced and moreover--as seen over the cross section of the bakingchamber--with ununiform velocity.

SUMMARY OF THE INVENTION

It is an object of the invention to avoid these drawbacks and to improvesupply of heated air to the baking good such, that the heated air issupplied with high velocity to the baking good carried by the carriageand the heat supply to the baking good is uniform over the whole bakingchamber. This object is achieved by the invention in that channels areprovided on the carriage, which, in inserted position of the carriage,adjoin the associated slots and are delimited by baffle plates providedin addition to the support members, air blown into the baking chambervia said slots being guided by the channels in direction to the centerof the carriage and onto the baking good. Said channels form in insertedposition of the carriage some sort of continuation of the air flowopenings provided in the partition wall, so that the air blown into thebaking chamber via these openings enters said channels at least for themajor part and becomes--corresponding dimensions of the cross section ofthese channels being provided--not substantially decelerated until thisair arrives at the baking good. Surprisingly, it has been found that inthis manner the baking good is uniformly subjected to the action of hotair and that the baking good becomes equally baked even if the air flowopenings are less uniformily distributed over the surface of thepartition walls than are walls usual up till now. Within the spirit ofthe invention it is now sufficient to provide slot-shaped air flowopenings only at those locations where said mentioned channels of thecarriage adjoin. Any additional air flow openings provided in thepartition walls between said channels have no effect whatsoever.

Preferably and according to the invention, one slot each is arrangedimmediately below the support members, noting that the carriage carriesbelow each slot a lying baffle plate limiting one of the channelstogether with the support member located above said baffle plate.Thereby, each support member forms one wall of a channel which resultsin saving construction material and furthermore in the advantage thatthe channels extend closely below the support members, so that theheated air flowing within the channels effectively heats the metallicsupport members (baking plates) for the dough portions to be baked andsimultaneously the air is blown from above onto the dough portionslocated within the corresponding compartment of the carriage.

According to a further development of the invention, the baffle plateand the support member extend in direction of the jet of air emergingfrom the slot and in parallel relation one relative to the other and inhorizontal direction. The cross section of the channel is thus kept atleast substantially constant from its end located adjacent the air flowopening of the partition wall till its end directed to the center of thecarriage, so that the speed of the air jet is substantially not changedalong the length of this channel.

According to a preferred embodiment of the invention, the arrangement issuch that a cover plate extends downwardly from that edge of the baffleplate, which faces the slot, and in direction to the support memberlocated beneath the baffle plate. In this manner, also parasitic jetsare utilized which enter the baking chamber via the airflow openings inthe partition walls, because these parasitic jets can now no more enterthe baking chamber and arrive at the baking good via the channels formedbetween the support members and the baffle plates but are passed by thedownwardly directed sections of the baffle plates into the channelsdelimited by these baffle plates. It is within the scope of theinvention, that the lower end of the cover plate is spaced apart adistance, preferably a horizontal distance, from the support members,the cover plate being located closer to the slot than the supportmember. The cover plate thus extends laterally outwardly from thecarriage for some extent. This arrangement reliably provides an exitopening for the air flowing out of the baking chamber. It isparticularly favourable if the cover plate passes over to the baffleplate via a bent portion. This facilitates introduction of the heatedair into the interior of the carriage as well as evacuation of theconsumed warm air out of the interior of the carriage in direction tothe suction openings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawing the object of the invention is schematically illustratedwith reference to an embodiment.

FIG. 1 shows a vertical section through the baking oven, seen in normaldirection relative to the direction of insertion of the carriage.

FIG. 2 is a section along line II--II of FIG. 1 and

FIG. 3 shows in a section similar to that of FIG. 1 and in an enlargedscale the arrangement of the baffle plate and of the cover plate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The baking oven has a heat-insulated housing 1 which can be tightlyclosed by means of a door 2 being provided with an inspection window 3.The housing 1 encloses a baking chamber 4 into which can be inserted acarriage 7 carrying the baking good 5 on support members 6 being formedof baking plates. This carriage 7 can be completely shifted out of thebaking chamber 4, therefore it can be completely separated from thebaking oven. For this purpose, the carriage has a chassis 8, the wheelsof which are guided on rails 9 provided on the bottom of the bakingchamber for securing the relative position of the carriage 7 within thebaking chamber 4. Within recesses 10 of the housing 1 on both sides ofthe chassis 8 there are provided means 11 for supplying bakingatmosphere.

The baking chamber 4 itself is tightly closed on top by a cover wall 12,from which one partition wall 13 each extends at both sides of thecarriage 7 and over the effective height of the baking chamber, that isthat height of the carriage 7, over which the support members 6 arearranged one above the other at uniform distances. Each partition wall13 has a plurality of horizontal air flow openings formed of slots 14and extending over the whole depth t (FIG. 2) of the carriage 7 asmeasured in direction of inserting movement of the carriage 7. Heatedair is alternately supplied to the slots 14 of both partition walls 13via two air channels 15 being separated from the proper baking chamber 4by the partition walls 13 and extending at both sides of the bakingchamber 4 over its whole effective height. the horizontal cross sectionof these air channels 15 may decrease from top to bottom (FIG. 1). Airis alternately supplied from the top to both air channels 15, said airbeing supplied by means of a blower 16 and being heated by a heatingmeans 17 of any desired type. In the embodiment shown, the heating meansis formed of a burner system, the heating means can, however, also beformed of an electric heating system, and so on. The blower 16 can be ausual ventilator, but preferably is a cross-flow blower, the rotor ofwhich has such a length that the air channels 15 extending at least overthe depth t of the carriage 7 are uniformly supplied with air at alllocations. Conveniently, the blower 16 and the heating means 17 arelocated above the baking chamber 4 and the air channels 15,respectively, in order to keep the width b (FIG. 1) of the ovenconstruction small. For alternately supplying the air channels 15 withheated air, the sense of rotation of the blower 16 is, convenientlyautomatically, reversible. This results in an air stream flowing indirection of the arrows 18 shown in full lines alternating with an airstream flowing in direction of the arrows 19 shown in dashed lines (FIG.1).

The slots 14 have only a comparatively small cross-sectional area, sothat the heated air supplied to these slots via the air channels 15enters the baking chamber 4 with high velocity from said slots 14. Inorder to ensure that this great velocity of the air is not substantiallyreduced prior to impingement of the heated air onto the baking good 5,the slots 14 are arranged at such a level that one slot 14 each islocated closely below each support member 6. Furthermore, a baffle plate20 is provided for each slot 14 and below the slot 14 for formingtogether with the support member 6 located above the associated slot 14a channel 21 through which the air emerging from the slot 14 is suppliedin direction to the center of the carriage 7. The sheet metal baffle 20extends in horizontal direction and in parallel relation to the supportmember 6 and, as measured in direction of the width b of the bakingoven, over approximately one fifth to one third, preferably toapproximately one fourth, of the width of the carriage 7. The baffleplates 20 are carried by the carriage 7. For this purpose, the carriage7 has at the four corners of its horizontal projection uprights 22carrying L-guides 23 arranged in pairs one above the other and in equaldistances, the support members 6 being inserted into these L-guides. Thebaffle plates 20 extend over the whole depth t (FIG. 2) of the carriage7, i.e. from upright 22 to upright 22. In order to prevent escape of theheated air from the channels 21 at front locations and rear locations,as seen in direction of inserting movement of the carriage 7, the rearwall 24 of the carriage 7 can be closed by a plate and the front side 25of the carriage 7 can be closed, for example by means of doors.

In order to prevent marginal jets of the heated air injected via theslots 14 from not being supplied through the channels 21 in direction tothe interior of the carriage 7 and thus from arriving in an uncontrolledmanner at the interior of the carriage 7 within residual area betweenthe uprights 22, a cover plate 26 (FIG. 1,3) is connected with eachbaffle plate 20 and extends in downward direction from that edge of thebaffle plate 20, which faces the slot 14. This cover plate 26 extends indownward direction and toward the support member 6 located below thebaffle plate 20 to such an extent, that its lower end 27 (FIG. 3) islocated at a somewhat higher level than the support member 6 locatedtherebeneath and approximately at the same level as the upper edge ofthe L-guide 23 carrying the support member 6. On account of the coverplates 26 being located somewhat outside of the uprights 22, thereremains a gap 28 between the upper edge of each L-guide 23 and the lowerend 27 of the adjacent cover plate 26 which gaps extends over the wholedepth t of the carriage 7 and provides an unobstructed flow passage forthe air which is to be extracted from the interior of the carriage 7 andto be fed to the suction slot 14. Under normal conditions, the coverplate 26 extends downwardly in vertical direction, but the cover platecan also be slightly inclined for the purpose of adjusting the width ofthe gap 28. Conveniently, the cover plate 26 is formed integrally withplate 20 via a bent portion 29, so that both plates 20, 26 can easily bebent from one single piece and there results a well suitable guide meansfor the air.

A wet vapor exhaust opening 30 (FIG. 2) can be provided at the back wallof the baking oven and this opening can be closed by a slide plate 31which can be adjusted in its height position in direction of the twinarrow, for example by means of a tackle. Furthermore, a vapor pressurerelief opening 32 can be provided in the rear wall of the baking oven,said opening being closable by means of a lid. Said both openings 30, 32provide the possibility to remove the wet vapors into a vapor exhaustchannel 33 arranged in the back wall of the housing 1.

I claim:
 1. A baking oven comprising:a housing; means for heating air;means, in fluid communication with the heating means, for blowing theheated air in alternating directions through a baking chamber; first andsecond partition walls disposed within and spaced apart from the housingfor forming first and second air channels extending a substantial lengthfrom a top to a bottom of the housing, the first and second air channelsbeing in fluid commuication with the blowing means for flowing heatedair received from the blowing means, the first and second partitionwalls defining said baking chamber therebetween and having a pluralityof apertures formed therein for flowing air from the first and secondchannels into the baking chamber; a carriage disposed stationarilywithin the baking chamber, the carriage including a plurality of supportmembers for carrying a baking good; means forming a further air channelon both sides of said carriage and opposite each other, each air channelincluding a support member and having an air inlet opening at that sideof the carriage which faces the neighboring partition wall, the airinlet opening being in fluid communication with one of said apertures,for forming an enclosed passage for guiding air flowing through said airinlet opening a substantial length toward a center of the carriage andabove the baking good, and further air channel means having an air exitopening facing the center of the carriage and being positioned spacedapart from a side of the carriage; and a cover plate extendingdownwardly from that end of the further air channel means adjacent theaperture and towards the support member located beneath the further airchannel means and forming with the support member located beneath thefurther air channel means a further opening for air flowing out of theinterior of the carriage.
 2. Baking oven according to claim 1 whereinone slot is arranged in each partition wall immediately below a supportmember and the carriage carries below each slot a lying baffle plate,the baffle plate together with the support member located above thebaffle plate defining one of the further channels.
 3. Baking ovenaccording to claim 2 wherein the baffle plate and the support memberextend in the direction of the jet of air emerging from the slot and inhorizontal parallel relation to each other.
 4. Baking oven according toclaim 3, wherein the lower end of the cover plate is spaced apart fromthe support member, the cover plate being located closer to thepartition wall than to the carriage, when measured in horizontaldirection.
 5. Baking oven according to claim 1, wherein the lower end ofthe cover plate is spaced apart a horizontal distance from the supportmember.
 6. Baking oven according to claim 1, wherein the cover plate isintegrally formed with the baffle plate via a bent portion.
 7. Bakingoven according to claim 1 wherein the apertures extend over the depth ofthe support members.
 8. A baking oven comprising:a housing; first andsecond partition walls disposed within and spaced apart from the housingfor forming first and second air channels extending a substantial lengthfrom a top to a bottom of the housing, the first and second partitionwalls defining a baking chamber therebetween and having pairs of opposedapertures therein for flowing air from the first and second channelsinto the baking chamber; a carriage disposed stationarily within thebaking chamber, the carriage including a plurality of baking platesvertically spaced from each other for carrying a baking good, eachbaking plate being disposed directly above a corresponding pair ofopposed apertures; a first baffle plate mounted in the carriage beloweach baking plate and in close proximity to the baking plate, the firstbaffle plate extending a substantial length toward a center of thecarriage and forming with a lower surface of the baking plate a thirdenclosed air channel adjacent to and in fluid communication with theaperture in the first partition wall beneath the baking plate forguiding the air flowing through the third air channel a substantiallength toward the center of the carriage and solely above the bakinggood; a first cover plate extending downwardly from that end of thefirst baffle plate adjacent to the aperture in the first partition walland toward the baking plate located beneath the first baffle plate andforming with the first baking plate located beneath the first baffleplate a further opening for air flowing out of the interior of thecarriage; a second baffle plate mounted in the carriage below eachbaking plate and in close proximity to the baking plate, the secondbaffle plate extending a substantial length toward the center of thecarriage and forming with a lower surface of the baking plate, a fourthenclosed air channel adjacent to and in fluid communication with theaperture in the second partition wall beneath the baking plate forguiding the air flowing through the fourth air channel a substantiallength toward the center of the carriage and solely above the bakinggood; a second cover plate extending downwardly from that end of thesecond baffle plate adjacent to the aperture in the second partitionwall and toward the baking plate located beneath the second baffle plateand forming with the baking plate located beneath the second baffleplate a further opening for air flowing out of the interior of thecarriage; and wherein the first and second baffle plates have free endsfacing the center of the carriage for forming an air exit openinglocated in the center of the carriage, facing downwardly and beingpositioned spaced apart from the side of the carriage, through which airexit opening the air flows downwardly for impinging against the bakinggood.
 9. The baking oven according to claim 8 further comprising meansfor alternately flowing air into one of the first or second airchannels.
 10. The baking oven according to claim 9 further comprisingmeans for supplying a baking atmosphere to the baking chamber. 11.Baking oven according to claim 8 wherein the baffle plates extendshorizontally and parallel to the baking plates over one fifth to onethird, of the width of the carriage.
 12. A baking oven comprising:ahousing; means for heating air; means, in fluid communication with theheating means, for blowing the heated air in alternating directionsthrough a baking chamber; first and second partition walls disposedwithin and spaced apart from the housing for forming first and secondair channels extending a substantial length from a top to a bottom ofthe housing, the first and second air channels being in fluidcommunication with the blowing means for flowing heated air receivedfrom the blowing means, the first and second partition walls defining,with a cover wall and a rear wall of the housing, said baking chambertherebetween and having a plurality of apertures formed therein forflowing air from the first and second channels into the baking chamber,the blowing means being disposed above the baking chamber, the junctionsof the rear wall of the housing with the partition walls and the coverwall being substantially air tight so that the heated air enters thebaking chamber from one of the air channels and leaves the bakingchamber through the other of the air channels; a carriage disposedstationarily within the baking chamber, the carriage including aplurality of support members for carrying a baking good; and meansforming a further air channel on both sides of said carriage andopposite each other, each air channel including a support member andhaving an air inlet opening at that side of the carriage which faces theneighboring partition wall, the air inlet opening being in fluidcommunication with one of said apertures, for forming an enclosedpassage for guiding air flowing through said air inlet opening asubstantial length toward a center of the carriage and above the bakinggood, the further air channel means having an air exit opening facingthe center of the carriage and being positioned spaced apart from a sideof the carriage; and a cover plate extending downwardly from that end ofthe further air channel means adjacent the aperture and towards thesupport member located beneath the further air channel means and formingwith the support member located beneath the further air channel means afurther opening for air flowing out of the interior of the carriage.